You might also combine the widget plugin with the shopping cart button html code. It should be reasonably easy to create a button that links to any product in your system and place the code for that in your widget. Your user can then access the products as you want them.

The only downside I can think of is you'll need to manage this going forwards and in a busy site adding new products and revising button codes, etc could be hard work. If your product set is reasonably static, then it shouldn't be an issue.